Analog-to-digital converters (hereinafter, abbreviated as “ADCs”) have been used in various technical fields. However, conversion speed and conversion accuracy (SNR) required in specification of the ADCs are not uniform. For example, in wireless communication systems used in digital mobile-phone services, various modulation methods are employed, and the conversion speed and the conversion accuracy required in ADCs for demodulation vary depending on the modulation methods.
In one example, while an ADC that performs demodulation in the Wideband Code Division Multiple Access (W-CDMA) system is required to have combined specification of relatively-high conversion speed and relatively-low conversion accuracy (SNR), an ADC that performs demodulation in a digital mobile telephony system standardized particularly in Europe (Global System for Mobile communication: GSM)) is required to have combined specification of relatively-low conversion speed and relatively-high conversion accuracy (SNR).
However, conventional ADCs have been independently developed on a case-by-case basis depending on required specification. Therefore, there is a problem in that development periods and development costs are increased.